In order to satisfy the increasing requirements of the large bandwidth high-speed mobile access, the Third Generation Partnership Projects (abbreviated as 3GPP) put forward a Long-Term Evolution advance (abbreviated as LTE-Advanced) standard. The LTE-Advanced reserves a core of a Long-Term Evolution (abbreviated as LTE) for the evolution of the LTE, and adopts a series of techniques to expand the frequency domain and the space domain based on the above, so as to realize the purpose of improving the utilization ratio of the spectrum, and increasing the system capacity and the like.
The Wireless Relay technique, namely, one of the LTE-Advanced techniques, aims at expanding the cell coverage area, reducing the blind angle (or dead angle) area in communication, balancing the load, transferring the service in the hotspot area, and saving the transmitting power of the User Equipment (abbreviated as UE). As shown in FIG. 1, the RN provides the functions and services similar with a normal eNB for the UE which is accessed to a cell of the RN, and then accesses an eNB which serves for the RN through a wireless interface in the similar mode of a normal UE; the eNB which serves for the RN is called as a Donor eNB (abbreviated as DeNB).
According to whether the RN has its own independent cells, or is taken as a part of a cell under the DeNB, a Type1 Relay and a Type2 Relay are respectively defined. The Type1 Relay refers that the RN can establish its own independent cells which have their own Physical Cell ID (abbreviated as PCI). The RN works as an eNB in its own cells, for example, transmitting reference signals, scheduling the UE, and the like. The Type2 Relay does not have its own independent cells and PCI, and is only used for assisting the DeNB to transmit data. Besides the Type1 Relay, a “Type1a” Relay and a “Type1 b” Relay are also defined in the standard, and are similar with the Type1 Relay in a cell establishment aspect; both the “Type1 a” Relay and the “Type1b Relay” have their own independent cells, and can independently receive and transmit control signals and perform the scheduling.
In view of the structure, the RN and the DeNB establish a unique S1 connection on the control plane, and the DeNB is taken as a unique Mobility Management Entity (abbreviated as MME), all the S1 signaling related to the UE will be transmitted to the DeNB through the S1 connection, the DeNB transmits the S1 signaling to a real MME destination on the S1 connection established by the DeNB and the MME. Similarly, the RN also only establishes a unique X2 connection with the DeNB, the X2 signaling between the RN and other eNBs must be forwarded through the DeNB.
It should be noted that, an Operation and Maintenance (abbreviated as OAM) of the RN cannot communicate with the OAM of the DeNB (for example, the two belong to different operators), thus, the cell parameters allocated by the OAM of the RN, such as an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (abbreviated as ECGI), may conflict with the ECGI of the cell managed by the DeNB, namely, the uniqueness of the ECGI is lost. So, the cell parameters of the cell managed by the RN are allocated by the DeNB, but not by the OAM of the RN. Thereby, the DeNB needs to know the number of the cells managed by the RN before allocating the cell parameters for the RN.